Safety switch



Jan. 20, 1953 A. M. LESSARD 2,626,328

SAFETY SWITCH Filed July 18, 1950 INVENTOR. H.M.LE55/lg0 Patented Jan.20, 1953 UNITED STATES PATENT OFFICE SAFETY SWITCH Alfred M. Lessard,Snoqualmie, Wash.

Application July 18, 1950, Serial No. 174,396

1 Claim.

This invention relates to safety switches for use in connection with thebatteries of automobiles, tractors, airplanes, etc., where instant andeasy opening of circuits supplied by a battery is desirable, especiallyfrom the standpoint of safety, convenience for repair of circuits andfor other reasons.

It is the principal object of this invention to provide a practical,safe, and efficient switch mechanism that may be easily and readilyapplied to a battery terminal, and which switch comprises as a partthereof, a terminal post that is adapted to be electrically connectedwith or disconnected from the battery terminal through the mediacy ofthe switch mechanism, and to which post a battery cable may be appliedin the same manner as it is ordinarily applied to the battery terminal.

It is also an object of this invention to provide a switch mechanism ofthe character above stated having circuit contacts adapted to be engagedor disengaged for the purpose of closing and opening a circuit betweenthe battery terminal to which the switch is applied and the terminalpost of the switch, and which contacts are mounted by hingedly joinedmembers with which a toggle linkage is associated and through whichlinkage the switch opening or closing action is effected.

It is a further object of the invention to provide a switch, as abovestated, wherein the toggle linkage is adapted to be manually actuated bya pull rod, cable, or the like, which may be extended to a point atwhich it is easily accessible to the operator of the vehicle in whichthe battery is used.

Still further objects of the invention reside in the details ofconstruction and combination of parts embodied in the device and in themode of use of the switch as will hereinafter be fully described.

In accomplishing these and other objects of the invention, 1 haveprovided the improved details of construction, the preferred forms ofwhich are illustrated in the accompanying drawings, wherein- Fig. 1 is aside View of a part of a battery, equipped with a safety switch embodiedby the present invention.

Fig. 2 is a perspective View of the present switch.

Fig. 3 is a vertical section through parts of the switch showing theterminal posts of the battery and switch and the switch contacts; theview being substantially on line 3-3 in Fig. 1.

Fig. 4 is an enlarged sectional detail on line 6-4 in Fig. 2.

Fig. 5 is an enlarged sectional detail on line 5-5 in Fig. 1.

Referring more in detail to the drawings- For purpose of illustratingthe use of the present switch I have, in Fig. 1, shown a portion of acommon form of storage battery and the usual form of battery cablewhereby a circuit connection is made with one terminal of the battery.The battery is here designated by numeral l6, and its terminals aredesignated at H and I2. The battery cable is designated by numeral l3and it is shown as being equipped with a split securing clamp l5,adapted to be applied to the terminal post 12 and tightened and securedby a clamp bolt 16.

The present switch, as best shown in Fig. 2, comprises a base memberwhich is in the nature of a securing clamp; this member being designated in its entirety by numeral 20. It comprises a horizontal mountingbar 2| formed with a tapered socket 2! opening to the under side thereofand adapted to receive the battery terminal post [2 therein. At one sideof the socket, the mounting bar is longitudinally split, as at 22, and aclamp bolt 23 is extended directly through the spaced end portions orlegs 24-45 at opposite sides of the split. At the other side of thesocket, the mounting bar is formed with two spaced, upwardly andoutwardly directed legs 25-45, between the upper ends of which one endof a switch lever 28 is pivotally mounted by a pivot bolt 26 that isextended horizontally through these parts.

The lever 28 extends along and over the mounting bar 2 l, and at thatend thereof which is opposite the end secured by pivot bolt 26, it isconnected to the ends of legs 24-45 of the mounting bar through themediacy of a switch actuating toggle linkage comprising a pair of links3ll3fi' pivotally connected by a pivot pin 3 I. Link 30 is pivotallyconnected at its upper end to the lever 28 by a pivot pin 32. Link 30 isconnected at its lower end to the legs 2G2Il of bar 2| by a pivot pin33.

An actuating rod 35 is connected, at one end, to the toggle linkagethrough the mediacy of the pin 3|. This rod may be extended to a dashboard, instrument panel, or to other position accessible to an operatorand there equipped with a suitable operating handle, not herein shown,whereby, by a pull on the rod, the switch will be opened and by a pushon the rod, the switch will be closed.

Formed as an integral part of the mounting bar 2|, at the top side anddirectly over the socket 2| is a circuit contact boss 40 in the form ofa horizontal disk. Likewise, formed on the under side of the switchlever 28 is a contact boss 4! in an opposed relationship to the contact40, and adapted to be flatly engaged therewith upon closing the switch,and to be disengaged therefrom when the switch is opened, thus to closeandopen a circuit through the switch.

As shown in Fig. 3, it is desirable that the contacts 40 and 4| be facedwith buttons of silver, or the like, indicated at 49m and 45a: in Fig.3, to provide better circuit connections and to avoid pitting. On thetop side of the switch lever 28 is an integral terminal post 43, pref--erably corresponding in size and. shape to, the terminal l2, and adaptedto have the cable clamp l5 applied directly thereto as shown in Fig. 1,

so that the same cable that ordinarily is applied to thebattery terminalpost 12, can be used with the switch.

The-switch 2G- is yieldingly held in closed position by one or morecoiled springs 44 which are applied-as shown in Fig. 1 across the togglelinkage. Preferably the ends of the springs 44 re. hooked over the endsof the toggle attaching pins 32 and 33.

To disengage the switch contacts, it is only required that a pull beapplied to rod 35 that will cause the straightening of the togglelinkage. This linkage, after passing from position shown in Fig. 1, veryslightly over dead center can be stopped, thus to prevent the springs Al again closing the switch. For such stopping of the linkage, the lowerend of link 38' has been extended, as at 36m in Fig. 1, so as to engageagainst a shoulder in one of the mounting legs 2 In order that openingof the switch will break the circuit connection the switch lever must beinsulated from the mounting bar 2!. In Fig. 4 it is shown that the pivotpin 26 is encased in an insulating sleeve 48 and the lever 23 is mountedfor pivotal action on the insulated sleeve and is spaced from the legs25 by insulating washers 4949 applied about the sleeve. Likewise, at theother end of the switch lever 28, the upper ends of the springs 44* areapplied to insulating bushings 59'fitted on the ends of pin 32. Thetoggle linkage is of Bakelite, or of other material that is electricallynon-conductive, thus there is not electrically conductive connectionbetween parts 2 I and 28 except through contacts E and 41.

To protect the contacts 4% and GI, it is desirable that they be enclosedin a compressible rubbersleeve 55, as shown in Figs. 1 and 3. This 4sleeve is located about the parts 40-4! between levers 2| and 28 andnormally encloses the contacts in a weather tight joint. It in no wayinterferes with the switch closing action.

Switches and operating mechanism of this kind afford easy and quickcomplete disconnection of the battery circuit from all instruments ormotors supplied with current thereby. It not only provides a quick andeasy means for disconnecting the battery for testing or repair of partsbut also is a safety device whereby all circuits may be opened in caseof emergency, as in crash landing of airplanes.

Switches of this kind may be made in various sizes and in variousdesigns without departing from the spirit of the invention.

Having thus described my invention, what I claim as new therein anddesire to secure by Letters-Patent, is:

A switch of the character described comprising a mounting barelectrically conductive material formed on its under side with adownwardly opening socket adapted to receive therein the terminal postof a typical automobile battery; and having a contact boss integraltherewith on its top side, intermediate its ends, a switch lever ofelectrically conductive material, disposed above and extending along thesaid mounting bar and having an insulated, hinged connection at one endwith the corresponding end of the bar and having a contact boss on itsunder side adapted to be engaged with and disengaged from the contactboss on the mounting bar to make and break a circuit connection, byhinging action of said lever, and having a terminal post formed thereoncorresponding in size and shape to the battery post for which themounting bar socket is designed to receive, spring means joining themounting bar and, lever to urge the contact bosses thereon together, anda linkage joining the bar and lever and operable to move them apart todisengage the contact bosses.

ALFRED M. LESSARD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,893,046 Austin Jan. 3, 19332,545,965 McCamon Mar. 20, 1951 FOREIGN PATENTS Number Country Date386,426 Great Britain Jan. 19, 1933

